- Increase in Sea Urchin Population: Sea otters are voracious predators of sea urchins which feed on kelp. With the decline of sea otters, the sea urchin population exploded.
- Overgrazing of Kelp Forests: The unchecked growth of sea urchins led to overgrazing of kelp forests. Kelp forms dense underwater "forests" that provided habitat and food for diverse marine species. As kelp forests declined, many dependent species lost their homes and food source.
- Disruption of Food Chains: The loss of kelp had a ripple effect throughout the food chain. Herbivores that relied on kelp for food suffered population declines, impacting carnivores that preyed on those herbivores. The entire ecosystem became less diverse and less resilient.
- Erosion and Loss of Habitat: Kelp forests acted as natural buffers that protected the coastline from wave action and storms. Without kelp, coastal erosion accelerated, destroying important habitats and affecting other organisms that depended on stable shorelines.
- Decline in Fish Populations: Kelp forests supported a complex ecosystem that provided food and shelter for many fish species. The degradation of kelp forests due to overgrazing by sea urchins ultimately led to declines in fish populations, affecting commercial fisheries and the livelihoods of coastal communities.
In summary, overhunting of sea otters disrupted the delicate balance of the marine ecosystem, causing a cascade of negative impacts such as population explosions of sea urchins, overgrazing of kelp forests, erosion, loss of critical habitats, and declines in fish populations. Sea otter restoration efforts were later undertaken to restore balance and ensure the long-term health of coastal ecosystems.
